I have done many of these and what seems to work for me is to place the assembly on a flat hard surface. Push down on the plastic with the spring under it and slide the steel pin out with a pair of needle nose pliers. DO NOT LET GO OF THE SPRING! This will enable more movement needed to insert both the large and small tabs of the handle. Also make sure that the latch is in the open position before sliding the pin back into place. There, that wasn't so hard now was it?